Air-heating apparatus



(No Model.)

2 Sheets-Sheet 1.y

J. BARTLETT.

Am HEATING APPARATUS.

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(NovModel.) 2 Sheets-Sheet 2.

J. BARTLETT. AIR HEATINGAPPARATUS.

Patented Jan. 19,1892.

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UNITED STATES JAMES BARTLETT,

PATENT OFFICE..l

OF TOLEDO, OHIO.

AIR-HEATING APPARATUS.

lSPIECIFICAIIION forming part of Letters Patent No. 467,145, datedJanuary 19, 1892.

Application iiled June 17, 1891.

T0 all whom t may concern.:

Be it known that I, JAMES BARTLETT, a citizen of the United States,residing at Toledo, in the county of Lucas and State of Ohio, haveinvented certain new anduseful Improvements in Air-Heating Apparatus, ofwhich the following is a specification.

My invention relates to apparatus used for warming air; and theinvention consists in a novel construction and arrangement of devicesfor that purpose, as hereinafter more fully described.

In the accompanying drawings, Figure l represents a central verticallongitudinal section of the apparatus on the line of Fig.

` 3. Fig. 2 is a transverse vertical section on the line 1/ y of Fig. l,and Fig. 3 is a front elevation of the furnace proper.

The object of this invention is to produce an apparatus for warming alarge volume-of air with a small amount of fuel, and to so construct itas to-consume the smoke and gases of combustion. It is designed moreespecially for warming buildings, particularly large buildings occupiedby many persons, and Where a large volume of fresh air is requisite,such' as schoolbuildings, theaters, churches, and the like. It is alsoapplicable for use in connection with dry-houses used for dryingmaterial of any kind.

To construct an apparatus on my plan I provide a series of metal tubes,preferably seven feet long and four inches in diameter, or thereabout,as I find that these proportions give the best results, though it isobvious they may be varied, more or less, without departing from theprinciple of myin vention. These tubes a, I mount or secure in plates band b at their ends, as shown in Fig. l, preferably using from forty toone hundred and forty tubes in a nest, according to size of heaterrequired, they being arranged parallel in horizontal and vertical rows,as shown in Fig. 2. rlhe tubes are inserted through holes in abaffle-plate e before being secured to one of the end plates, as shownin Fig. 1,the tubes being open at both ends to permit a free passage ofthe air through them. I then construct a furnace, preferably ofbrick-work, of the form shown, the sides and top being arched, as shownin Fig. 2, the rear part of the arch being inclined downward, as repre-Serial No. 396,577. (No model.)

sented in Figs. l and 2, thus forming an overhead chamber of fire-brick,which when once heated aids to render the combustion therein moreperfect, the heated gases and products passing out at the depressed andrelatively narrow throat at the rear. 'lhc furnace is provided withsuitable grate-bars I, with an ash-pit below, the bottom of which iscomposed of a metal plate set in the walls of the brickwork and inclinedtoward the front for convenience in removingl the ashes. is composed ofa metal plate provided with a door for the fuel-chamber and another forthe ash-pit, in the usual manner. By an examination of Fig. 2 it will beobserved that the fuel-box is only abouthalf as wide as thecombustion-chamber above.

In order to consume the smoke, I locate at the lowerV side of the throatthrough which the products of combustion escape or pass from thecombustion-chamber a curved perforated plate J, preferably made in theform of a box, open along its Linder side, as shown in Fig. l, therebeing an open space underneath this plate and which communicates withthe ash-pit, so that air "can pass freely from the ash-pit into thisspace, and from thence through the perforations in jets and mingle withthe products of combustion as they pass this air uniting with the heatedproducts of combustion and consuming whatever of smoke there may be,this combustion being rendered more perfect bythe ai-r being heated asit passes through the ash-pit in contact With the depending Webs of thegrate-bars and the highly-heated plate J. In order to regulate theamount of air thus supplied, I locate a valve Z at the lower edge ofplate J and conend of which projects at the front, so that the valve canbe opened more or less or be closed entirely, as circumstances mayrequire. The furnace being thus constructed, IV mount the nest ofair-tubes before described directly over the furnace, as shown in Fig.l, they being set at an angle of forty-five degrees or thereabout, soasto cause the air which enters at the front or lower ends to pass alongtoward and out at their upper rear ends as it becomes heated and thuscreate a continuous current of air through the tubes The front t nect itby an elbow-lever h with a rod t', the

from the combustion-chamber, the oxygen of IOS a. This nest ofair-heating tubes is supported by and incased in briclvwork, which maybe a continuation of the vertical walls of the furnace, as shown in Fig.2, the top being either arched or supported by iron bars, as shown inFig. l. i

lo enable the tubes to be cleaned ol soot, dzc., I locate a man-holewith a removable cover C centrally over the tubes, as represented inFigs. l and c,and at the rear under side I also provide one or moreopenings with detachable covers for the removal of the soot and ashes,as shown at n, Fig. l.

I arrange a smoke-pipe F transversely in the lower rear part of thechamber in which the air-tubes are set, as shown in Figs. 1 and 3,thispipe having a hole d cut in it near each end, as indicated by dottedlines in Fig. S, for the smoke or gases to enter from the chamber, t-hispipe being connected with any suitable flue. By this arrangement thegases are taken equally from near each side of the chamber, and are thuskept more evenly distributed over and in contact with all the tubes thanwould be the case were they taken at a single opening. If preferred,instead of these two holes this pipe F mayhave a narrow slit extendingits entire length within the chainber and thus secure even greateruniformity of draft and distribution of the gases across the entirechamber. Its opposite end is made to project through the wall, as shownin Fig. 3, and is provided with a detachable stopper or cover, so thatby removing the same the pipe can at any time be cleared of ashes. Therear under portion of the casing or chamber in which the tubes are set Iprefer to make of a metal plate E, set in the brick-work, as shown inFig. l. By this construction and arrangement of the parts it will beseen that the heat passes from the throat of the furnace onto and aroundand among the tubes a at their lower ends, where the air as it entersthem is cold, and which cold air thus prevents the tubes from beingburned out or injured by the heat. The heat passes upward among andaround the tubes in front of the baffleplate e, over the top of thelatter, and then down among and around the tubes in rear of said plateto the smoke-pipe at the bottom of the chamber, and thence out throughthe smoke-pipe F, by which the heat is effectually utilized, it beingabsorbed by the air passing through the tubes with which it is thus heldin intimate contact during its passage through the chamber. By usingtubes of the diameter mentioned the friction of the air in passingthrough them is not sufiicient to materially retard its flow, whiletheir length is suflicient to absorb the heat and effectually transferit to the air, the amount of heatingsurface being relatively muchgreater than in ordinary heating-furnaces, and thus farbetter resultsare secured from the consumption of a given amount of fuel by thisapparatus.

In setting the cluster of lues their front plate b will be securedpermanently to the brick-work, while their rear plate b may rest on aniron beam G, as shown in Fig. l, there being a small groove e formed inthe brick- \vork for the edges of the plate to rest in and allow for itsmovement caused by the expansion and contraction of the tubes, thisjoint being packed with asbestus or other suitable material to render itsmoke-tight; or, if preferred, the rear end maybe made fast and thefront end be arranged to move slightly, that being a matter of choice orconvenience for the builder.

By arranging the opening for the admission of air to the tubes at theend or side opposite to the furnace-doors, as shown in Fig. 1, it willbe seen thatI avoid the influx of ashes or dust, of which more or lessescapes when the ash-pit or furnace-door is opened, and, if desired, auair-duct may be extended from the mouth of the tubes to the outer air,thus securing a sure supply of pure fresh air at all times. The rear endof the chamber into which the warm air is delivered from the tubes willof course be connected with the fines for conducting it to the variousrooms of the building, and these may be of brick or metal, as may bemost convenient.

In cases where a very large volume of air is required a fan may belocated at the mouth of the tubes, as shown by dotted lines in Fig. l,and when it is desired to use the apparatus in connection withdry-houses for the drying of material a fan will necessarily be used,and it may be located so as to either force or draw the air through thetubes, as may be most convenient.

IVhile I have given the size and proportions which I deem necessary tosecure the best results, I do not limit myself to them, as

j, it is obvious that they may be varied somewhat and still give goodresults. So, too, while I prefer to set the tubes at an angle offorty-five degrees, it is obvious they may be varied somewhat and stilloperate nearly as well. If placed horizontally, however, the air willnot pass through them to the desired extent, if at all, unless a fan orsome equivalent means be used to impart motion toit, and if the tubes bevaried somewhat in diameter and length the operation will still be thesame in principle and dilfering only in degree. It is also obvious thatinstead of a hinged valve for regulating thesupply of air to thesmoke-burner a slide-valve or register may be used and be operatedeither from the front or from the side of the furnace, as may bepreferred, these being merely matters of detail to be determined by themanufacturer, builder, or engineer in charge.

I am aware that tubular heaters for bot-h air and water have before beendescribed and that smoke-consuming devices of various kinds have beenapplied to furnaces; also that fans have been used to force air bothbefore and after it has been heated, and that smokepipes have had theirends arranged to project through the walls of a furnace to enable themIOC IIO

to be cleaned from the exterior, and therefore I do not claim eithor ot'these devices separately considered; but I am not aware that any one hasbefore devised an apparatus like mine, and therefore What I claim as myinvention isl. The herein-described heating apparatus, consisting of aseries of open-ended air-tubes set at an inclination within aheat-chamber, and a furnace having its upper wall inclined downwardtoward the throat through which the products of combustion enter theheatchamber, said throat being arranged directly7 under the air-tubes ator near the end where the cold air enters said tubes, the whole beingconstructed and arranged to operate substantially as and for the purposeset forth.

2. The combination, in an airheating apparatus, of a furnace having itsupper wall or roof inclined downward toward the throat or exit-openingfor the smoke and gases, and a smoke-consuming device consisting of aperforated plate with an air-inlet underneath the same arranged directlyunder said throat or exit, and a series of open-ended air-tubes arrangedat an inclination within a heat-chamber directly over said furnace,substantially as shown and described.

In witness whereof I hereunto set my hand in the presence of twowitnesses.

lJAMES BARTLETT.

Witnesses:

H. H. NEWMAN, O'Zerk U. S. Consulate-Gencrdl, London, Eng- Zcmfl.

GEORGE C. IIITT, U. S. Vice- @amid-General, London, England.

